Endless Summer produces blooms on both old and new wood so yours should be blooming throughout the summer. If it is getting adequate sunshine (sounds like it is) and is regularly watered, it should produce enough new growth during the season to continually produce flowers. The only thing that might halt flower production is overfertilization. Too much nitrogen will result in lots of green growth at the expense of flowers. It's a bit late in the season for your hydrangea to begin producing flowers for this season, but for next year, hold off on fertilizer applications (lime is okay) until your hydrangea starts blooming. Then, if you feel it really needs to be fed, use half as much fertilizer as listed on the label. This way you'll be supplying needed nutrients without the change of overdosing on nitrogen. Best wishes with your hydrangea!